/* Global Styles */
:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --info-color: #17a2b8;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    color: #333;
    padding-top: 56px;
}

/* Navigation */
.navbar {
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%) !important;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    padding: 0.8rem 0;
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color) !important;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.navbar-brand i {
    font-size: 1.8rem;
}

.navbar-nav {
    margin-left: 2rem;
}

.nav-item {
    position: relative;
    margin: 0 0.5rem;
}

.nav-link {
    color: var(--dark-color) !important;
    font-weight: 500;
    padding: 0.5rem 1rem !important;
    border-radius: 4px;
    transition: all 0.3s ease;
}

.nav-link:hover {
    color: var(--primary-color) !important;
    background-color: rgba(0,123,255,0.1);
}

.nav-link.active {
    color: var(--primary-color) !important;
    background-color: rgba(0,123,255,0.1);
}

.nav-link i {
    margin-right: 0.5rem;
}

@media (max-width: 991.98px) {
    .navbar-nav {
        margin-left: 0;
        padding: 1rem 0;
    }
    
    .nav-item {
        margin: 0.25rem 0;
    }
    
    .nav-link {
        padding: 0.75rem 1rem !important;
    }
}

/* Header Sections */
.header-section {
    background-color: #f8f9fa;
    padding: 2rem 0;
    margin-bottom: 2rem;
}

.header-section .lead {
    max-width: 600px;
    margin: 0 auto;
}

/* Calculator Styles */
.calculator-section .card {
    border: none;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.calculator-section .card-header {
    background-color: #fff;
    border-bottom: none;
    padding: 1.5rem 1.5rem 0.5rem;
}

.calculator-section .card-body {
    padding: 1.5rem;
}

.calculator-section a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color 0.2s;
}

.calculator-section a:hover {
    color: var(--primary-color);
}

/* Category Blocks */
.category-block {
    text-align: center;
    padding: 1.5rem;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    height: 100%;
    transition: all 0.3s ease;
}

.category-block:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.category-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto;
    background: var(--light-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    transition: all 0.3s ease;
}

.category-block:hover .category-icon {
    transform: scale(1.1);
    color: var(--dark-color);
}

.category-block ul {
    text-align: left;
    margin-top: 1rem;
}

.category-block a {
    color: var(--secondary-color);
    text-decoration: none;
    display: block;
    padding: 0.5rem 0;
    transition: color 0.2s;
}

.category-block a:hover {
    color: var(--primary-color);
}

/* Footer */
footer {
    background-color: var(--light-color);
    padding: 3rem 0;
    margin-top: 3rem;
}

footer h5 {
    color: var(--dark-color);
    font-weight: 600;
    margin-bottom: 1rem;
}

footer a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

footer a:hover {
    color: var(--primary-color);
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-section {
        padding: 1.5rem 0;
    }

    .calculator-section .card {
        margin-bottom: 2rem;
    }

    .category-block {
        margin-bottom: 2rem;
    }
}

/* Accessibility */
:focus {
    outline: 3px solid var(--primary-color);
    outline-offset: 2px;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    border: 0;
}

/* Print Styles */
@media print {
    .no-print {
        display: none !important;
    }
    
    body {
        padding-top: 0;
    }
    
    .calculator-section .card {
        box-shadow: none;
        border: 1px solid #dee2e6;
    }
    
    .category-block {
        break-inside: avoid;
    }
}